Aseptic Technique Flashcards

Questions and Answers

What is an inoculum?

The inoculating instrument used to transfer bacteria.

The bacteria transferred to a new medium. (correct)

The bacteria that are undesired within a culture.

The sterile medium to which bacteria will be transferred.

Which of the following best describes aseptic technique?

To flame the inoculating loop.

To keep the environment sterile.

To use chemicals to inhibit or destroy bacteria.

To manipulate bacteria without introducing contaminants. (correct)

Name the steps of loop sterilization in their correct order.

Attach burner to gas source. Adjust air intake. 2. Turn on gas. 3. Light burner with striker. 4. Adjust air supply. 5. Heat loop until entire wire glows red. 6. Cool loop.

This video shows a student improperly sterilizing an inoculating loop. What is the student's mistake?

The wire portion of the instrument was not adequately heated. Signup and view all the answers

A student properly flames her loop but then forgets to let it cool. What is the most important issue associated with this mistake?

The hot loop may create aerosols when it touches the culture. Signup and view all the answers

If a student forgets to flame the mouth of a broth culture tube before transferring culture to it, what might result?

The medium in the tube might become contaminated. Signup and view all the answers

This video shows a student incorrectly obtaining an inoculum from a broth culture. What is his error in aseptic technique?

The cap of the tube was not handled correctly. Signup and view all the answers

What error in aseptic technique most likely caused this contaminant colony to grow on this agar slant?

Failure to flame the mouth of tube. Signup and view all the answers

Study Notes

Inoculum and Aseptic Technique

Inoculum: Refers to the bacteria transferred to a new sterile medium during inoculation; it should ideally consist only of the desired species without contaminants.
Aseptic Technique: Involves manipulating bacteria without introducing contaminants; essential for maintaining culture purity, often includes flaming culture tube openings.

Loop Sterilization Steps

Attach burner to gas source and adjust air intake.
Turn on the gas and light the burner with a striker.
Adjust air supply for proper flame characteristics.
Heat the inoculating loop until the entire wire glows red before cooling it.

Loop Sterilization Errors

Inadequate Heating: If the wire portion of the inoculating loop does not glow red, it may not be properly sterilized, risking contamination of cultures.
Cool Before Use: A hot loop can create aerosols upon contact with broth cultures, potentially spreading bacteria and posing inhalation risks.

Culture Tube Handling

Failing to flame the mouth of a broth culture tube before transferring culture can lead to contamination as airborne bacteria may enter when the cap is off.
Proper handling of the tube cap is crucial; placing it on the bench may lead to contamination when reattached.

Identifying Contamination Causes

A contaminant colony in an agar slant is often due to failure in flaming the mouth of the culture tube, allowing airborne bacteria to enter.
Always ensure proper aseptic technique to minimize the risk of contamination in microbiological procedures.

Description

Test your knowledge of aseptic techniques with these flashcards. Focus on key terms and definitions related to bacterial inoculation and sterile mediums. Perfect for students in microbiology courses seeking to master aseptic practices.